This invention relates to a novel process for filling dental cavities. Co-pending application Ser. No. 415,454, filed Nov. 12, 1973, by the inventors hereof relates to an improved dental filling composition comprising certain monomeric compositions which are described in detail herein. Briefly, these compositions comprise polymerizable urethane-acrylate resins which cure by a free-radical mechanism, along with a free-radical initiator. While these compositions do function well for their intended purpose, because of the polymerization inhibiting effect of oxygen on compositions of this nature, the surface cure of the compositions when applied to a dental cavity is sometimes not reliably completed. It has now been found that surface cure properties can be improved by use of the present process.